1. Field of the Invention
The present invention relates to a method and apparatus for printing an image on a paper or product in a production path; and more particularly, to a method and apparatus for purging, cleaning and parking one or more print heads of such an imager.
2. Description of the Related Art
Known printing systems have print heads arranged over printing or production paths designed to print thousands of product per hour. The printing paths may be adapted to provide printed product that may include sheets of paper, envelopes, boxes, etc.
The known printing systems have one or more print heads that must be periodically serviced in order to maintain the quality of print provided on the printed product. The servicing typically includes cleaning the print head. During a cleaning cycle, the printing system is not printing the product so it is desirable to clean the print heads as quickly as possible to maximize the printing throughput of the printing system. For example, if the cleaning cycle takes two to three minutes to clean the print heads, then two to three hundred units of printed product may not be printed per cleaning cycle. Moreover, if the print heads have to be cleaned, for example, once per hour, then two to three thousand units of printed product may not be printed during a ten hour business day. Therefore, there is an economic advantage to cleaning the print heads as quickly and efficiently as possible.
In one known printing system, the printing assembly must be moved laterally off and away from the printing or production path in order to wipe and clean the print heads. One disadvantage of this approach is that it takes time to move the printing assembly off the printing or production path, time to clean the print heads, and time to move the printing assembly back into the printing or production path to resume printing the product. Moreover, known systems also have to purge between the belts, purge on the belt or purge on a product that will be discarded. From a practical standpoint, an operator could likely remove and manually wipe the pens quicker than the cleaning station when done automatically.
In view of the aforementioned, there is a need in the industry to clean more quickly and efficiently print heads arranged in a printing or production path. There is also a need in the industry to prevent pen dry-out and provide no print loss on a first image sprayed after a period of inactivity (as little as 30 seconds).